1. Field of the Invention
The invention relates to an improved fuel injection device for an internal combustion engine with direct fuel injection.
2. Description of the Prior Art
A fuel injection device with which the fuel can be injected directly into a combustion chamber, assigned to it, of an internal combustion engine is known on the market. For that purpose, a valve element is disposed in a housing, and in a region of a fuel outlet opening, the valve element has a pressure face that acts overall in the opening direction of the valve element. On the opposite end of the valve element, there is a control face acting in the closing direction, which defines a control chamber. The control face acting in the closing direction is larger overall than the pressure face that when the valve element is open acts in the opening direction.
When the fuel injection device is closed, in a region of the pressure face acting in the opening direction aid of the control face acting in the closing direction, a high fuel pressure prevails, of the kind furnished for instance by a fuel collection line (or “rail”). For opening the valve element, the pressure applied to the control face is lowered, until the hydraulic force resultant, acting in the opening direction, at the pressure face exceeds the force acting in the closing direction. As a results opening of the valve element is accomplished.
A prerequisite for the mode of operation of this fuel injection device is sealing between every region in which the comparatively small pressure face, acting in the opening direction, is present, and the region of the valve element in which the comparatively large control face, acting in the closing direction, is present. Leakage fluid, in the known fuel injection device, is carried away from the region of the seal via a leakage line.
The object of the present invention is to refine a fuel injection device of the type defined at the outset in such a way that it is as simple and economical as possible in construction and can be used at a very high operating pressure.